Developing a Model-View-Controller (MVC) Component for Joomla!1.6 – Part 05

http://docs.joomla.org

Introduction

This tutorial is part of the Developing a Model-View-Controller (MVC) Component for Joomla!1.6 tutorial. You are encouraged to read the previous parts of the tutorial before reading this.

Adding a variable request in the menu type

For the moment, the displayed message is always Hello World!. Joomla!1.6 gives the possibility to add parameters to menu types. In our case, this is done in the site/views/helloworld/tmpl/default.xml file:

site/views/helloworld/tmpl/default.xml

<?xml version="1.0" encoding="utf-8"?>  <metadata>  	<layout title="COM_HELLOWORLD_HELLOWORLD_VIEW_DEFAULT_TITLE">  		<message>COM_HELLOWORLD_HELLOWORLD_VIEW_DEFAULT_DESC</message>  	</layout>  	<fields name="request">  		<fieldset name="request">  			<field  				name="id"  				type="list"  				label="COM_HELLOWORLD_HELLOWORLD_FIELD_GREETING_LABEL"  				description="COM_HELLOWORLD_HELLOWORLD_FIELD_GREETING_DESC"  				default="1"  			>  				<option value="1">Hello World!</option>  				<option value="2">Good bye World!</option>  			</field>  		</fieldset>  	</fields>  </metadata>  

Two important things to note:

  • the request group of fields indicates mandatory fields
  • the array parameter that indicates that these parameters will be added in the request URL [??]

The model has to be modified in order to switch between the two different messages (which is chosen by the user with the field defined above):

site/models/helloworld.php

<?php  // No direct access to this file  defined('_JEXEC') or die('Restricted access');     // import Joomla modelitem library  jimport('joomla.application.component.modelitem');     /**   * HelloWorld Model   */  class HelloWorldModelHelloWorld extends JModelItem  {  	/**  	 * @var string msg  	 */  	protected $msg;     	/**  	 * Get the message  	 * @return string The message to be displayed to the user  	 */  	public function getMsg()   	{  		if (!isset($this->msg))   		{  			$id = JRequest::getInt('id');  			switch ($id)   			{  			case 2:  				$this->msg = 'Good bye World!';  			break;  			default:  			case 1:  				$this->msg = 'Hello World!';  			break;  			}  		}  		return $this->msg;  	}  }  

Also modify your helloworld.xml file to indicate the new version:

helloworld.xml

<?xml version="1.0" encoding="utf-8"?>  <extension type="component" version="1.6.0" method="upgrade">     	<name>Hello World!</name>  	<!-- The following elements are optional and free of formatting conttraints -->  	<creationDate>November 2009</creationDate>  	<author>John Doe</author>  	<authorEmail>john.doe@example.org</authorEmail>  	<authorUrl>http://www.example.org</authorUrl>  	<copyright>Copyright Info</copyright>  	<license>License Info</license>  	<!--  The version string is recorded in the components table -->  	<version>0.0.5</version>  	<!-- The description is optional and defaults to the name -->  	<description>Description of the Hello World component ...</description>     	<update> <!-- Runs on update; New in 1.6 -->  		<schemas>  			<schemapath type="mysql">sql/updates/mysql</schemapath>  		</schemas>  	</update>     	<!-- Site Main File Copy Section -->  	<!-- Note the folder attribute: This attribute describes the folder  		to copy FROM in the package to install therefore files copied  		in this section are copied from /site/ in the package -->  	<files folder="site">  		<filename>index.html</filename>  		<filename>helloworld.php</filename>  		<filename>controller.php</filename>  		<folder>views</folder>  		<folder>models</folder>  	</files>     	<administration>  		<!-- Administration Menu Section -->  		<menu>Hello World!</menu>  		<!-- Administration Main File Copy Section -->  		<!-- Note the folder attribute: This attribute describes the folder  			to copy FROM in the package to install therefore files copied  			in this section are copied from /admin/ in the package -->  		<files folder="admin">  			<!-- Admin Main File Copy Section -->  			<filename>index.html</filename>  			<filename>helloworld.php</filename>  			<!-- SQL files section -->  			<folder>sql</folder>  		</files>  	</administration>     </extension>  

You can test this variable request by putting index.php?option=com_helloworld&id=1 or index.php?option=com_helloworld&id=2 in your browser address.

Packaging the component

Content of your code directory

Create a compressed file of this directory or directly download the archive and install it using the extension manager of Joomla!1.6. You can add a menu item of this component using the menu manager in the backend.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s